In a surprise announcement, Mr Low Thia Khiang has said he will not contest the post of secretary-general of the Workers' Party (WP) at its next Central Executive Council election, due next year.
Speaking at the party's 60th anniversary celebration last night, he said he was leaving the party's top post after achieving the two goals he set for himself as leader - electoral progress and party renewal.
"We now have a team of younger leaders who are ready to drive the party forward," he said, adding that he was stepping down to enable younger leaders to take over the party completely, now that they have formed a cohesive team that connected well with the grassroots.
When he steps down as secretary-general next year, Mr Low would have led the party for 17 years. He took over the post from Mr J.B. Jeyaretnam in 2001.
Mr Low entered politics in 1988, losing in his first outing as a WP candidate in Tiong Bahru GRC. He became MP after winning the Hougang seat at his second election in 1991, and has served as MP since.
The history books will remember Mr Low as the first opposition leader to win a group representation constituency. He led the WP team to victory in Aljunied GRC in the 2011 election. The team retained it in the 2015 election.
Party members and volunteers told The Straits Times that Mr Low's biggest contribution is building up the WP as an institution that is not over-reliant on him.
Former WP Non-Constituency MP Yee Jenn Jong said: "This has been something he has been preparing the party for, for some time. He is conscious of his role in building the party up as an organisation, rather than something centred around a single person."
Party volunteer Soh Keng Sian, 49, a mechanic, said Mr Low has sacrificed much for the WP.
"Maybe he can play a more supporting role now as an adviser. He can help the younger leaders because of his experience," he said.
WP volunteer Jeff Ng, 24, felt a change of leadership would inject fresh ideas into the party, saying: "I think this is a good thing that will help take the party forward."
Dr Gillian Koh of the Institute of Policy Studies said: "Tonight's announcement is certainly a surprise. Mr Low is only 61 and seems like he still has a lot of fight in him... Perhaps there is a need to clear the way for younger members of the party to take over the reins."
Political observer Derek da Cunha said: "It is no secret that there has been a clamour by one section of the WP rank and file, and quite a number of the party's ardent supporters, for a more robust opposition to the PAP.
"As head of the WP, Mr Low has been relatively taciturn, which has not necessarily been a bad thing especially after the disastrous state of opposition politics following the 1997 General Election.
"But that approach, together with running a tight ship, is slowly being overtaken by other developments."
Present at the celebratory dinner last night were over 1,200 guests, and leaders from the party, including the WP's six elected MPs and three Non-Constituency MPs.
The mood at the dinner - held at the Ban Heng Pavilion Restaurant at HarbourFront Centre - was lively. Guests took turns to approach WP MPs to chat with them and ask for their autographs.
Party chairman Sylvia Lim said the WP's Aljunied-Hougang Town Council (AHTC), which has been plagued by financial and governance lapses, now has its own integrated town council management software, thanks to the "meticulous direction" of AHTC vice-chairman Png Eng Huat.
Referring to the WP's town council woes and its 2015 election showing, where it lost one of its seats, assistant secretary-general Pritam Singh saluted members who kept the party going through hard times. "Many members closed ranks and slogged through with the party in the trenches," said Mr Singh.
• Additional reporting by Charissa Yong